Internal-combustion engine.



. J. STILL.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED 050.5,1913

Patented June 19, 1917.

2 SHEETS-SHEET 1.

* WILLIAM JOSEPH STILL, or LONDON, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent. v

- Patented une 19,1917.

Application filed December 5, 1913. Serial No. 804,927.

To all whom it may concern:

Be it known that I, WILLIAM JOSEPH STILL, of London, England, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

TlliS'lIlVGIlUOIl relates to improvements in and connected with internal combustion engines and has reference to engines of this type adapted to operate also under steam generated wholly or partially by heat derived from the combustion cylinder walls and from the combustion exhaust, and the object of the present invention is a more eificient utilization of the heat of the combustion engine for the generation of steam.

The invention consists primarily in a par ticular arrangement and mode'of operation whereby feed water preheated by the exhaust from the combustion engine in its final condition, i. 6. immediately before it finally passes from the exhaust pipe, is evaporated in the cylinder jacket and the steam thus produced superheated by the exhaust from the combustion engine in its initial condi; tion, i. e. as it leaves the combustion chamber. This combustion exhaust is then utilized in a boiler to evaporate further preheated water and the exhaust inits final condition is as aforesaid employed for the preheating of feed water. Steam thus produced is introduced into the combustion engine cylinder and is expanded therein in contact with one side of the piston which divides it from the combustion.

By the use of additional supplies of fuel, however, the combustion .cylinders can be employed as high pressure cylinders and the steam exhausted from these cylinders can be utilized in a low pressure steam cylinder or' cylinders, and a convenient. arrangement would be to have a two cylinder combustion engine whose cranks are at 180 and operate as high pressure steam cylinders and exhaust to a common double acting low pressure steam cylinder with its crank set at 90. Of course this latter arrangement could be duplicated and four combustion high pressure cylinders utilized in conjunction with two low pressure steam cylinders. Further the exhaust steam from the combustion cylinders when such cylinders are employed as high pressure cylinders can be utilized to operate a steam turbine.

This reheating will however in any case occur owing to the contact of the steam with" the heated surfaces of the combustion cylinder and piston and thus a very effective cycle is provided which may be summarized as fol- Evaporation of water into steam is effected in the combustion cylinder jackets and in a boiler by means of added fuel and probably also by the combustion exhaust. Slight superheat of the steam is effected by the waste heat in the combustion engine exhaust, the steam is then admitted to the back of the combustion pistons andcoperates expansively at the sanie time taking up heat from the piston cylinder, after which it is exhausted to any suitable low pressure motor as for instance to a low pressure cylinder. or cylinders on the main shaft and thence is exhausted to a condenser.

When a class of fuel unsuited for use within a combustion engine, such for instance as coal, can be tpurchased at a low cost relatively to that of the fuel necessary for operating the combustion engine, the construction in accordance with the foregoing conditions, enables power to be obtained from a proper combustion of both fuels at a lower cost than by the use of either singly. The cycle is as follows: Combustion is produced within the internal combustion engine cylinder (or cylinders) by the use of the more expensive fuel, and the cylinders of the comsteam in locomotivesand by mixing with the air to heat it previous to its combustion with the lower priced fuelin the furnace of these boilers.

The steam evaporated in the boiler is added to that evaporated in the jackets, supplied to the combustion engine and expanded behind the main pistons during the return or compression strokes.

mentioned the steam is further expandedv in priced fuel with which they are supplied.

A closed stoke-hold under a small air pressure. (as from afan) should be employed to balance the pressure due to the exhaust so as to facilitate 'stoking and check gas'leak age through casing joints; the volume of air to be delivered to maintain this pressure will be small as the main supply is forced by the exhaust, and little if any is required above the grate to assist combustion.

The combustion engine is used to greater advantage in that the mean. steam pressure within it is greatly increased and the heavy construction required to withstand combustion pressure more fully utilized, the lower pressures inherent to extreme expansions being more cheaply dealt with in a lightly con structed low pressure cylinder or an exhaust turbine.

In the accompanying drawings I have illustrated an engine constructed and operating in accordance with the foregoing general principles, Figure 1 being asectional elevational View of the engine comprising two separate combustion cylinders each of the opposed piston type and each provided with a pair of steam cylinders at the backs of the pistons, and including also two low pressure cylinders. Fig. 2 is a diagrammatic view of the boiler arrangements. Fig. 3 is a diagram illustrating the method of utilizing the waste heat of the exhaust gasesfor generating and superheating steam and preheating feed water for the boiler.

In the drawings the combustion side of the engine operates on the two-stroke cycle system. It is supplied with a mixture of hydrocarbon vapor and air (or air only if working on the Diesel cycle) under pressure by a pipe 1 which leads to annular chambers 2 around the cylinder 3. This chamber communicates with the interior of the cylinder 3 by way o f,a ring of ports 4 which are uncovered by the piston 5 at the end of the working stroke. 'The exhaust is by way of a ring of ports 6 and an annular chamber 7 both'of which are similar to those described above, to the common. exhaust pipe 8. The plpe 9 conveys heated feed water to the bottom of the jacket 10 which feed water. is

' evaporated therein. The steam produced is gases from the internal combustion engine drawn ofi at the top of the jacket by the pipe 11. This steam, after being superheated in the superheatere (Fig. 3) by'the exhaust in their initial condition, is conducted by pipes 12 to jackets 13 around the cylinders 3 which are in communication with valve In Fig. 2 I have illustrated diagrammatically the method I prefer for inducing the necessary air supply for 'efiecting the combustion of-the fuel beneaththe boiler. The numeral 19 designates a nozzle or group of nozzles through which the combustion engine exhaustafter it has been utilized for superheating steam. as in superheater e, and preheating feed water as in preheater f- 1s injected into the ash-pit 20'. The inrushing exhaust gases induce a-supply of air to the furnace, which air completes the combustion of the exhaust gases and supplies the furnace 21 with oxygen.

Fig. 3 shows diagrammatically the preferred method of carrying out my invention. The combustion exhaust is led from cylinder '3 by.pipe 8 to the superheater B and then to theboiler D by pipe J. From the boiler D the exhaust gases pass by the pipe K to the feed Water preheater E and from thence to the vash pit of the boiler by the pipe .19. .The, preheated feed Water is supplied to the jacket of the combustion engine cylinder through the pipe Wby means of feed pump M Which also delivers feed water to the check valve of the boiler through the pipe N. Steam is taken from the top of the combustion cylinder jacket and boiler by pipe 11 and thence to superheater. Superheated steam is --then conducted by pipes P and 12 to the valve chest of the steam cylinders at the ends of the combustion cylinder, the'exhaust steam being delivered to the valve chests of the low pressure cylinders F by means of the pipes R R. The final exhaust from the low pressure .cylinders passes to the condenser G by way of ipes' S S and T; If preferred, the pipe -R etween the high pressure cylinders and the low pressure cylindersanay be interrupted to contain a reheater R.

the removal and replacement of the ash tray the guillotine door 25 of'the ash pit rests upon the cover 24 and therefore falls immediately the ash tray is clear of it. vThus negligible escape of blast is all that is pos-' sible.

What I claim and desire to secure by Letters Patent is: v l

1 1. In-an internal combustion engine adapt ed to operate partially under steam, a combustion cylinder, a cylinder jacket forming part of a. steam generator, a steam superheater, connections for leading steam from the generator to the superheater, a. feed water heater, connections leading the combustion exhaust from the cylinder to'the steam superheater and thence to the feed water preheater.

2; In an mternal combustion engine adapted to operate partially under, steam, a combustion cylinder, a steam generation system, a steam superheater, a feed water preheater, connections leading water i from the preheater to the steam generator system, connections leading the combustion exhaust from the cylinder to the steam superheater, thence to the steam generator and thence to the feed water preheater.

into said :preheater and for leading water from said preheater to said cylinder jacket,

'said cylinder having a piston therein, and

one half of the cylinder being arranged to serve as a steam cylinder, a steam connection between said jacket and the steam side ,of the cylinder, a'steam superheater, said der, exhaust connections between said com- 3-. In an internal combustion engine adapted to operate partially under steam, acornbustion cylinder, a steam generation system including an ash pit, a steam superheater, a feed water preheater, connections leading water from the preheater to the steam generator system, connections leading the combustion exhaust from the cylinder to the steam superheater, thence to the steam generator, thence to the feed water preheater, and thence to nozzles located in the ash pit of the steam generator.

4. In an internal combustion engine adapted to operate partially under steam, a combustion cylinder, a cylinder jacket associated with a steam generator, a steam generator, a steamsuperheater, connections leading steam from the cylinder jacket and steam generator to the steam superheater, a feed water heater, connections leading the. feed water to the steam generator and cylinder jacket, connections leading the exhaust gases from the engine cylinder to the superheater thence to the generator and thence to the feed water preheater 5. In an internal combustion engine adapted to operate partially under steam, an internal combustion cylinder, a jacket for said cylinder, a preheater, connections for leading water into said preheater and for l d-' mg water from said preheater to said cy mder, a steam superheater, steam connections from said jacket to said superheater, and exhaust connections'from said cylinder to said superheater and from thence to said preheater. v

6. A prime mover comprising in combination, a combustion cylinder havinga jacket,

a preheater, connections for leading water bustion cylinder and the ash pit of said furnace, said last mentioned connections having an ejector nozzle to induce a flow of air into the ash pit, means for abstracting heat from the exhaust of said combustion cylinder prior to its entrance into the ash pit, and an arrangement for burning said exhaust in the furnace;

8. In an internal combustion engine adapted to operate partially under steam, a

combustion cylinder, a cylinder acket forming part of a steam generator, a steam superheater, connections for leading steam from the generator to the superheater, a feed water heater, connections leading the com bustion exhaust from the cylinder to the steam superheater and thence to the feed water preheater, and steam connections leading from the steam superheater to the steam side of the engine.

9. In an internal combustion engine adapted to operate partially under steam, a combustion cylinder, a cylinder jacket forming part of a steam generator, a steam super heater, connections for leading steam from the generator to the superheater, a feed water heater, connections leading the combustiom exhaust from the cylinder to the steam superheater and thence to the feed water reheater, and steam connectionsleading from the steam superheater to a cylinder operating as a high'pressure steam cylinder and connections whereby the steam exhausted from the-high pressure steam cylinder passes to a low pressure steamoperated member.

10. In an internal combustion engine adapted to operate partially under steam, a

combustion cylinder, a cylinder jacket forming part of a steam generator, a steam superheater, connections for leading steam from the generator to the superheater, a feed water heater, connections leading the combustion exhaust from the cylinder to the llti s team superheater and thence to thef'eed reheated prior to its expansion in the low 10 water preheater, steam connections leading pressure member.

from the steam superheater to a cylinder op- In testimony whereof I aflix my signaerating as a highpressure steam cylinder, ture in presence of two witnesses.

connections whereby the steam exhausted from the high pressure steam cylinder WILLIAM JOSEPH I passes to a low pressure steam operated Witnessesp member alnd means whereby the steam ex- ALFRED AUGUSTUS THORNTON, hausted from the high pressure cylinder is O. J. WORTH. 

